The present invention relates to a system for maintaining signal security in a communication network, and more particularly to a method and apparatus for fielding multiple versions of security in a subscription television system while maintaining signal scrambling compatibility.
There are many schemes for preventing the theft of signals in communication networks. Such networks can comprise, for example, subscription television systems including those that broadcast television programming by satellite or over cable. To date, no "unbreakable" security scheme has been developed. In the past, it has been difficult and expensive for a communication system operator to recover once the security of a system has been compromised. The wholesale replacement of existing subscriber terminals to implement a new security system each time an old system is breached is simply not practical.
Previous attempts to increase the difficulty of breaking a security system have, at best, only succeeded in extending the amount of time it takes to break the system.
It would be advantageous to provide a system wherein recovery from a security breach can be implemented with relative ease at a low cost. Such a system should preserve compatibility with an existing base of subscriber terminals. The system should also be easy to implement without inconvenience to subscribers.
The present invention provides a system having the aforementioned features and advantages.